A seismometer is an instrument that measures the motion of the ground due to seismic activity generated by earthquakes, volcanic activities, or other sources. A seismometer can be used to map the interior of the earth and to measure the size and locations of these sources of seismic activity. In principle a seismometer is also a vibration sensor. Low cost and high sensitivity seismometers are in high demand for distributed sensing of seismic activity.
Various types of seismometers are available such as pendulum-based seismometers and accelerometers using piezoelectric or microelectromechanical (MEMS) sensors. Many of these seismometers are good for strong motion detection. However, low cost, weak motion detection sensors are still lacking. See, for example, Merchant, “MEMS Applications in Seismology,” Seismic Instrumentation Technology Symposium, November 2009 (31 pages).
Thus, improved motion detector sensor designs would be desirable.